Anisotropic AlSi10Mg plate lattice structures via LPBF single-laser-track exposure: microstructural integrity, mechanical behavior and lightweight efficiency

Abstract

Abstract Thin-walled plate lattice structures fabricated from AlSi10Mg via laser powder bed fusion (LPBF) promise exceptional stiffness-to-weight ratios for lightweight applications. However, wall thicknesses below $$\sim {500}{\upmu }{\textrm{m}}$$ commonly introduce geometric variations, surface roughness, porosity, and strong crystallographic texture, which degrade mechanical performance. This study investigates a stretching-dominated anisotropic plate lattice structure with $${200}{\upmu }{\textrm{m}}$$ walls, derived from a 2.5D honeycomb topology and optimized for uniaxial and multiaxial loadings. Overhang-free design of this structure enhances reproducibility and dimensional accuracy. An additional advantage of the parallel continuous plates is that they enable direct analytical calculation of effective mechanical properties via rule of mixtures. An adapted single-laser-track exposure strategy (wall thickness-to-spot size ratio $$\sim {1.25}$$ ) suppresses downsizing effects, producing a homogeneous microstructure with a fine, intact eutectic cellular network free of coarsened Si regions. Measured–simulated deviations stay in the single-digit percentage range: normalized by relative density ( $$\rho ^*$$ ) axial Young’s modulus and yield strength closely match literature values for dense, peak-aged LPBF AlSi10Mg, while transverse values reach $$\sim {30}{\textrm{GPa}}$$ and $$\sim {117}{\textrm{MPa}}$$ ( $$\rho ^*={0.267}$$ ), respectively. Finite element models incorporating CT-derived geometry of a lattice cell and EBSD-based orientation data show that texture reduces axial Young’s modulus by up to $$\sim {5.5}\%$$ . While intra-cell geometric fluctuations contribute $$\le {2}\%$$ to the normalized Young’s modulus, inter-cell variations can introduce $$\sim {10}\%$$ scatter of absolute stiffness, which dominates the residual sample-to-sample differences. Strategic fillets at plate intersections enhance overall lightweight efficiency of this anisotropic metamaterial by improving transverse specific stiffness and elongation at break.